Decorated injection moulded product, and a method for producing the same

ABSTRACT

A method for producing an injected moulded product includes producing a first injection moulded layer having an external and an internal surface, of which the external surface is directed towards a front face of the injection moulded product. A foil is attached to the first injection moulded layer. The foil has first and second sides, and there is at least one pattern on the foil. The foil is placed against the internal surface of the first injection moulded layer. The injection moulded product may include a second injection moulded layer so that the first injection moulded layer, the foil and said second injection moulded layer constitute, in this order, an integral layered structure. The first side of the foil is next to the internal surface of the first injection moulded layer and said second injection moulded layer is next to the second side of the foil.

TECHNOLOGICAL FIELD

The invention concerns generally the technology of producing injectionmoulded products. Especially the invention concerns the technology ofproducing such products that have certain features that originate froman in-mould decorating process.

BACKGROUND OF THE INVENTION

Injection moulding refers to the procedure of manufacturing products byinjecting molten plastic material into a carefully designed mould thatdefines a cavity having the form of the desired end product. In-moulddecorating may be generally understood to denote any technology, whichapplies text, pattern or image to a moulding as a part of the mouldingprocess. In a more limited sense, which is also used in this patentapplication, in-mould decorating refers to a process where a decorativeinsert is placed into a mould before injecting molten plastic materialinto the mould. The word “decorative” should be understood widely,because in addition to purely aesthetic purposes the insert and/or thegraphic objects carried by it may have e.g. informative or protectivefunctions. From the technology of injection moulding there is known alsothe use of three-dimensional mechanical objects as inserts thattypically serve as mechanical reinforcements, but in in-mould decoratingapplications the insert comes almost invariably in the form of a thinthermoformable foil, the base material of which is typicallypolycarbonate or an alloy thereof.

FIG. 1 is a cross-sectional diagram that illustrates certain phases of avery simple in-mould decorating process. Patterns 101 are first formedonto the surface of a foil 102 through screen printing or other suitablepattern-forming process. The patterned foil 102 is formed to make itconform to the three-dimensional form of the mould, which (mould) itselfis not shown in FIG. 1. Several alternative methods are known forexecuting the forming step, such as vacuum or thermoforming, pressureassisted vacuum forming or the high pressure forming technologydeveloped by the German companies Bayer and Niebling HDVF. In additionto converting the form of the foil from two-dimensional tothree-dimensional, the piece of foil 102 belonging to a single workpieceis cut and trimmed to size, transferred to the moulding operation aswell as positioned and secured into the mould. The plastic material isthen injected into the mould so that it fuses onto the back of the foil102 to form the bulk of the end product 103. Note that the relativethicknesses of the foil 102 and patterns 101 are greatly exaggerated inall drawings for the sake of graphical clarity. In the final product thedecorative patterns 101 are clearly visible because they form thetopmost layer on the surface of the product.

The disadvantage of having the printed patterns fully exposed on theoutmost surface of the product is that the resistance of such a productagainst mechanical wear is poor. One of the most prominent areas ofapplication for in-mould decorated plastic products are the outer coversof mobile telecommunications devices, which are constantly carried alongin pockets, purses and bum bags where friction takes its toll on theoutmost surface.

FIG. 2 illustrates how a protective coating 201 can be applied onto theoutmost surface of the product e.g. by spraying it through a nozzle 202.This way the mechanical stability of the patterned surface can beremarkably enhanced, but the development comes at the cost of adding astage to the manufacturing process. Many protective lacquers compriseeasily evaporated solvents that are potential sources for fire andenvironment hazards in the manufacturing plant, which makes their useunattractive. The use of a separate coating layer makes themanufacturing process also more vulnerable to dust and other impuritiesin air.

FIG. 3 illustrates another solution to the problems concerning themechanical stability of the decoration. A transparent foil 102 is usedas the carrier of the decorative patterns 101, which are printed ontothe inner surface (so-called second surface) of the foil instead of itsouter surface like in FIGS. 1 and 2. In the final product the patterns101 become sandwiched between the transparent foil 102 and the plasticbody part 103 so that the former protects the patterns against externalfactors. This approach involves also certain difficulties that aremainly related to the patterns' poor resistance against the erosioncaused by the hot, molten polymer resin that flows into the mould andalong the printed surface of the foil.

FIG. 4 illustrates a double foil solution where instead of a single foila laminated structure of two parallel foils 401 and 402 is used. Thepatterns 403 are formed on either the lower surface of the upper foil401 or the upper surface of the lower foil 402 so that in the laminatedfoil structure they are enclosed in between the foils. The laminatedstructure is formed, cut and trimmed into size just as if it was asingle foil in some of the above-described methods, after which it isplaces into the mould and the plastic bulk part 404 is injection mouldedonto its inner surface. Using two parallel foils and laminating themtogether has, however, proven to be somewhat problematic because thefoil structure tends in some cases to become visible on the surface ofthe completed product. Additionally the process becomes rather complexand involves a relatively large number of processing steps.

Previous patent publications that more or less concern the technology ofdecorating injection moulded products or articles comparable thereto areabundant. Known to the applicant at the priority date of this patentapplication are EP 0 199 708, EP 0 383 364, EP 0 430 310, U.S. Pat. No.4,275,116, U.S. Pat. No. 4,717,615, U.S. Pat. No. 4,837,072, U.S. Pat.No. 4,994,224, U.S. Pat. No. 5,053,260, U.S. Pat. No. 5,714,231, U.S.Pat. No. 5,795,527 and U.S. Pat. No. 5,800,759.

SUMMARY OF THE INVENTION

It is an object of the present invention to present a decoratedinjection moulded product which is easy to manufacture, has excellentresistance against external wear and facilitates high yield in massproduction. It is also an object of the present invention to present amethod for manufacturing said decorated injection moulded product.

The objects of the invention are achieved by providing an injectionmoulded layer on the outside of the decorated foil that constitutes theinsert in the injection moulding process, either by injection mouldingon top of the foil or by injection moulding the product in concern in atleast two injection moulded layers so that the decorative patterns andtheir carrier foil are inserted between said layers before injectionmoulding the latter one of them.

The invention applies to an injection moulded product comprising:

-   -   a first injection moulded layer having an external surface and        an internal surface, of which the external surface is directed        towards a front face of the injection moulded product,    -   a foil attached to the first injection moulded layer, the foil        having a first side and a second side, and    -   at least one pattern on the foil;        the product is characterised in that it comprises a second        injection moulded layer, and that the first injection moulded        layer, the foil and said second injection moulded layer        constitute, in this order, an integral layered structure where        the first side of the foil is next to the internal surface of        the first injection moulded layer and said second injection        moulded layer is next to the second side of the foil.

The invention applies also to a method for manufacturing an injectionmoulded product, comprising the steps of:

-   -   producing patterns on a foil,    -   injection moulding a first injection moulded layer, and    -   placing the foil next to said first injection moulded layer; the        method is characterised in that it comprises the step of    -   injection moulding a second injection moulded layer onto the        entity comprising the first injection moulded layer and the        foil, so that the first injection moulded layer, the foil and        said second injection moulded layer come to constitute, in this        order, an integral layered structure where a first side of the        foil is next to an internal surface of the first injection        moulded layer and said second injection moulded layer is next to        a second side of the foil.

An injection moulded plastic layer at the outmost surface of aninjection moulded product offers excellent resistance against frictionalwear and damages that result from external impacts, at least whencompared to the modest durability of an insert foil made ofpolycarbonate. If the outmost layer is additionally at least partlytransparent to electromagnetic radiation at the wavelengths of visiblelight, decorations or other patterns that are inside it can be observedfrom the outside. A further injection moulded plastic layer beneath thepatterns may serve a multitude of purposes ranging from structuralenforcement to providing depth to the visual appearance of thedecoration.

According to a first aspect of the invention the (at least partly)transparent outmost layer is injection moulded first, without placingthe decorative insert meant by the invention into the mould yet at thisstage. The preformed insert is then placed against the inner surface ofthe already injection moulded transparent layer, and another layer ofplastics is injection moulded onto the inner surface of the structurethus formed so that in the final product the insert remains between theinjection moulded layers.

In order to protect the printed patterns on the insert layer from theerosion of the flowing polymer resin during the second injectionmoulding step it is advisable to have a non-printed surface as the onewhich comes against the second-step layer. This is most easily achievedby using a single insert foil printed on one side only so that theprinted side comes against the first-step injection moulded layer.However, the invention does not preclude the use of multilayeredlaminated inserts where patterns may come on multiple surfaces but wherethe inner surface of the innermost layer is non-printed to that saidinnermost layer acts as a protective layer. Even having patterns on thesurface which comes against the second-step injection moulded layed isnot completely excluded, provided that the problem of stability againstflowing molten polymer resin can be solved e.g. by using some specificink that has the required durability.

According to a second aspect of the invention the decorative insert isproduced first and placed into the injection mould against the core orkernel of the mould. The (at least partly) transparent outmost layer isthen injection moulded on top of the foil, where the direction-relatedterm “on top” means that the injection moulded layer becomes theintended outer surface of the final product.

In addition to purely aesthetic decoration the invention can be used formany other purposes. The “decorative” pattern that is, as a result ofusing at least the first aspect of the invention, truly enclosed withinthe bulk material of an injection molded product is very well protectedagainst unauthorised tampering, which means that a suitably designedpattern may serve as some kind of an authenticity certificate of theproduct. For similar purposes the pattern may have specificcharacteristics that are only observable under ultraviolet light or someother exceptional environmental conditions. If parts of an apparatus,which is located within an injection moulded cover, should be constantlyavailable for visual observation while other parts should be hidden, apattern layer may be used to keep the parts of the latter kind out ofsight. If the “decorative” pattern layer is electrically conductive, itcan even be used as a part of the electromagnetic shielding of the innercomponents.

In addition to the printed foil insert, also the bulk of the injectionmoulded layer(s) may be used to play a role in the decorative effect.For example colouring agents, metallic flakes or fluorescent orphosphorescent dyes can be mixed into the polymer resin so that theygive the injection moulded part(s) a certain advantageous visualappearance. Because the outmost layer is much better visible than theinner layer(s), its material and properties can be optimised for goodvisual properties. In the products according to the first aspect of theinvention the innermost layer need not be visible to the user at all, orat least it is much less visible than the outermost layer. Therefore itsmaterial and properties can be optimised for some other factors likestructural stiffness and/or ease of adapting its inside for themechanical attachment of the inner parts of the device.

BRIEF DESCRIPTION OF DRAWINGS

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings.

FIG. 1 illustrates the production of a decorated injection mouldedproduct according to prior art,

FIG. 2 illustrates the production of another decorated injection mouldedproduct according to prior art,

FIG. 3 illustrates the production of another decorated injection mouldedproduct according to prior art,

FIG. 4 illustrates the production of another decorated injection mouldedproduct according to prior art,

FIG. 5 illustrates the principle of the present invention,

FIG. 6 illustrates a method according to an embodiment of the invention,

FIG. 7 illustrates a variation of the principle of FIG. 5,

FIG. 8 illustrates another variation of the principle of FIG. 5 and

FIG. 9 illustrates another variation of the principle of FIG. 5.

FIGS. 1 to 4 were discussed above in association with the description ofprior art, so the following description of the invention and itsadvantageous embodiments focuses on FIGS. 5 to 9.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 5, which shows all parts schematically in cross-section, a foil501 is provided as the carrier of decorative patterns 502. Both the term“decorative” and the term “patterns” should be understood broadly,because the graphical objects carried by the foil 501 can serve amultitude of purposes in addition to being just aestheticallydecorative, and they may include various object types including bot notbeing limited to lines and two-dimensional shapes, bitmaps, hues andbackground colours, alphanumerical characters, photographic imagery andareas possessing various degrees of reflectivity or transparency. Anytypes of foils that are known to be applicable to in-mould decoratingcan be used as the foil 501; typically the foil consists of one orseveral layers of polycarbonate film. The foil 501 itself may have somebasic (opaque or translucent) colour or it may be completelytransparent. It may even consist of several differently coloured areasor patches. The foil 501 does not need to be continuous, although acertain degree of continuity is advantageous in terms of automated massproduction. The foil 501 may comprise openings therethrough.

A first injection moulded part 503 is also provided. This part is toconstitute an outer layer of the end product, and according to theinvention it is at least partly transparent or translucent to visiblelight. In the following we denote the first injection moulded part 503as the outer layer for short. The outer layer 503 may have some basic(opaque or translucent) colour or it may be completely transparent. Itmay even consist of several differently coloured areas or patches, andeffect materials such as metal flakes or dyes can be mixed to thepolymer resin from which the outer layer 503 is injection moulded inorder to give it a specific appearance. The effect materials may havedynamically changing properties such as a changing tone according toultraviolet radiation incident on the material or phosphorescent orfluorescent glow in the dark. The outer layer 503 does not need to becontinuous and it may comprise openings therethrough. The foil 501 withits patterns 502 is preformed to correspond to the form of the innersurface of the outer layer 503. The preformed foil 501 is placed againstthe inner surface of the outer layer 503 most advantageously so that anon-patterned surface of the foil is the one which remains accessible onthe inner surface of the combination.

A second injection moulded part 504, known also as the inner layer forshort, is injection moulded onto the inner surface of the combinationconsisting of the outer layer 503 and the patterned, preformed foil 501so that the inner layer 504 at least partly encloses the foil 501 inbetween the outer and inner layers. The functions of the inner layer 504in the combined structure are generally physical and functional ratherthan aesthetic or decorative, although it may also take part inproducing the outer appearance of the end product. The physical andfunctional nature of the inner layer 504 is to interpreted so that itprovides mechanical support and rigidity to the combined structure andserves as means for attaching the structure, which is most likely anouter cover or the visible face of an electronic device, to the innercomponents of the device in question. Other parts such as light guides,latch and hinge mechanisms or parts thereof and threaded nuts can beplaced within the inner layer 504 as inserts, and/or the inner layer maycomprise portions that serve as holders for such other parts. The innerlayer 504 may also have some basic (opaque or translucent) colour or itmay be completely transparent. It may consist of several differentlycoloured areas or patches, and in case it has a role to play indecorating the end product, effect materials such as metal flakes ordyes can be mixed to the polymer resin from which the inner layer 504 isinjection moulded. The inner layer 504 does not need to be continuousand it may comprise openings therethrough.

What is visible from the outside of the end product depends on theoptical characteristics of the outer and inner layers and the patternedfoil. One of the basic approaches in applying the invention is suchwhere the inner layer 504 is not visible to the outside at all. This ismost easily accomplished by using a transparent or translucent outerlayer 503 and an opaque foil the opacity of which comes either from thefoil material 501 being opaque or from the foil material being coveredby a continuous, opaque pattern 502, or from both. Another approach isto use the colour of the inner layer 504 as the background colour forthe end product and to use partially transparent or translucent outerlayer 503 and foil 501, 502 so that the background colour is visible atthose locations where no opaque patterning exists in outer layer orfoil. Numerous alternative approaches can be derived from the use ofmulticoloured inner and outer layers, perforations in one or several ofthe layers and the foil and similar variations around the basicstructural idea.

For the sake of graphical clarity of the appended drawings the patterns502 only appear on the flat upper surface of the structure of FIG. 5. Itis clear, however, that the invention does not place any limitations tothe location of the patterns on any surfaces of the injection mouldedproduct. Indeed it is a known major advantage of in-mould decoratingthat the patterns can be placed at arbitrary locations of thethree-dimensional end product. Also for the sake of graphical clarityonly the outer and inner layers appear in FIG. 5 to have even thicknessthroughout the layer, which is not a requirement that should be placedto the application of the invention. One of the visual effects producedthrough the application of the present invention might well be suchwhere the outer layer 503 varies remarkably in thickness so that thepatterned foil 501 is much closer to the overall outer surface of theend product at some locations that at some other locations. Combiningthis effect to a relatively heavy shading tint in the material of theouter layer 503 produces an interesting effect where the patterns 502that are printed on the foil 501 appear to gain a third dimension. Thevarying thickness of the outer layer 503 may also be used to provide alens effect where a detail of the patterned foil 501 appears to anobserver in magnified or reduced size.

One of the effects of the foil 501 is to keep the plastic materials ofthe outer and inner layers isolated from each other. This may beparticularly advantageous if the inner and outer layers are made of sodifferent grades of plastic that bringing them into close contact wouldcause harmful effects, such as diffusion of dye substances from onelayer to another. The foil may also act in the same way as the internalpolymer film of laminated glass structures, enhancing the mechanicalstrength of the overall structure. If the foil, the patterns or partsthereof are electrically conductive, they may also act as a part ofelectromagnetic shielding to the electronic components that thestructure consisting of the layers and the foil is to cover. If theinner and outer layers are transparent or translucent, but a certaincomponent or other part inside the structure consisting of the layersand the foil should be hidden from unauthorised visual inspection, anopaque area in the foil can be used to cover the location of thatcomponent or other part.

FIG. 6 illustrates a method for producing the in-mould decorated productshown in FIG. 5. At step 601 there is provided a base foil which is toact as the support, bonding and protective structure of the patternedfoil. To prepare for the patterning step there may be needed preparatorysteps, two examples of which are shown in FIG. 6: at step 602 there areprovided other foils which or parts of which are to be attached to thebase foil in order to produce the patterning, and at step 603 there areprovided the printing screens through which the patterns are to bescreen printed onto the base foil as well as the appropriate inks. Theinvention does not limit the number and nature of such preparatorysteps. The patterning step is shown generally as step 604. It maycomprise any forms of patterning, including but not being limited toscreen printing, offset printing, digital printing, etching, holographicpicture generation, painting, sputtering, plating, perforating, glueingand placing stickers onto the base foil. Also more exotic operationssuch as attaching light guides, resistors or other electronic componentsto the foil structure qualify as patterning.

After the patterning step there comes the preforming step 605 where thepatterned foil is preformed to conform to the inside of the outerinjection moulded layer. This step belongs to the usual known form ofin-mould decorating. The invention does not limit the selection of thepreforming method. In association with, or just as well separate from,the preforming step it is possible to cut and trim the piece of foilcoming into a single workpiece as is illustrated by step 606. It is notobligatory to cut and trim the foil at all at this stage, if themanufacturing apparatus allows the continuous foil to be led into themoulding step. Handling a continuous foil strip is sometimes moreadvantageous from the viewpoint of mass production than placingseparately cut pieces of preformed foil into the moulds.

In order to produce the outer layer of the moulding, a mould has beenclosed at step 607 and polymer resin has been injected into the mould atstep 608. The grade of resin and the set of moulding parameters to beused at step 608 have most advantageously been selected to fulfilldemanding criteria of good transparency or translucency, pleasant feeland visual appearance. At step 609 the mould is opened. What happensnext depends on the mould technology which is used. It is possible toremove the newly injection moulded outer layer from the mould altogetherand to place it into another, completely separate mould where the foiland the inner layer are to be added thereto. However, unnecessaryejection of workpieces from moulds is to be avoided if the quality ofthe moulding should be good: at the priority date of this patentapplication it is regarded as more advantageous to open the mould atstep 609 so that the newly injection moulded outer layer remains withina part of the mould, and change or adjust the other part(s) of the mouldin order to prepare for the injection moulding of the inner layer. Thesurface of the outer layer onto which the foil is to be applied mustnaturally become exposed when the mould is opened.

At step 610 the patterned, preformed and possibly also cut and trimmedfoil is placed into the mould and against the appropriate surface of theouter layer. At step 611 the mould is closed, and at step 612 morepolymer resin is injected into the mould in order to produce the innerlayer and to fuse the outer layer, the foil and the inner layer into anintegrated structure. The grade of resin and the set of mouldingparameters to be used at step 612 can be either the same as or differentfrom those that were used at step 608. Using different grade of resinand/or different moulding parameters enables the manufacturer tooptimise the second injection moulding step to fulfil criteria of e.g.good structural stiffness rather than fine external features. At step613 the mould is opened, and at step 614 the completed product isejected from the mould. Surface finishing treatments and varioustrimming and upgrading steps may follow thereafter like in knowninjection moulding processes.

The invention covers also such structures and methods where more foillayers than one or more injection moulded layers than two are used. FIG.7 illustrates schematically the production of an injection mouldedproduct for which there are first laminated two foils 701 and 702together. At least one surface of at least one of the foils comprisespatterns 703. After laminating the two foils together or in associationtherewith the foil structure is preformed. An outer layer 704 isproduced by injection moulding, and the preformed foil structure isattached to the inner surface of the outer layer. Finally an inner layer705 is injection moulded to the inside of the whole packet.

FIG. 8 illustrates schematically the production of an injection mouldedproduct for which there is provided a first foil 801 with patterns 802on one side. The patterned first foil 801 is preformed, and an outerlayer 803 is injection moulded. The preformed, patterned first foil 801is placed the patterned side first against the inner surface of theouter layer 803, and an intermediate layer 804 is injection moulded ontothe inside of the combined outer layer 803 and first foil 801. A secondfoil 805 is provided with patterns 806 on its one side. The patternedsecond foil 805 is preformed and placed the patterned side first againstthe inner surface of the combination consisting of the outer layer 803,the first foil 801 and the intermediate layer 804. Finally an innerlayer 807 is injection moulded to the inside of the whole packet. In theend product there are three injection moulded layers, separated fromeach other by the patterned foils. If all patterns should be visible forexternal visual inspection, at least the outer and intermediate layersmust be at least partly transparent or translucent.

So far the main emphasis of the preceding discussion has been in theapplication of the invention for decorative purposes, which means thatthe outer layer(s) must be at least partly transparent or translucent.However, it is also possible to present an embodiment of the inventionwhere at least one of the patterns on the patterned foil is meant to actas a secret security code, the existence of which within an injectionmoulded product can only be verified by using specific equipment. Forexample, the secret security code pattern may be made of a thin metallayer sputtered or otherwise generated onto a surface of the foil. Atthe location of the secret security code there is at least onestructural layer on each side of the secret security code that is opaqueenough to hide the secret security code from visual inspection undernormal conditions. These layers are, however, permeable to X-rays orother suitably energetic electromagnetic radiation which penetratesthrough the other opaque layers but does not penetrate the secretsecurity code or is at least remarkably attenuated by the materialthereof. Under normal conditions it is therefore impossible to say,whether the injection moulded product contains the secret security codeor not, while the question is easily solved by placing the product intoa transillumination device employing said suitably energeticelectromagnetic radiation.

FIG. 9 is an enlarged cross-sectional diagram of a part of an injectionmoulded product according to an embodiment of the invention. Here thesecret security code feature is associated to the decorative use of theinvention. The product comprises an injection moulded outer layer 901, afoil 902 and an injection moulded inner layer 903, of which only theouter layer 901 is transparent or translucent to visible light. On theouter surface of the foil 902 there are decorative patterns 904 whichare to be visible through the transparent or translucent outer layer901. However, at either the same location or at least partly at adifferent location of the foil and on the inner side of it there is asecret security code pattern 905 which is hidden from normal visualinspection, because the opaque foil 902 hides it from outside and theopaque inner layer 903 hides it from the inside. The secret securitycode pattern 905 is only observable in a transillumination device whichilluminates the product with other electromagnetic radiation thanvisible light, for which other electromagnetic radiation the outer layer901, the decorative patterns 904, the foil 902 and the inner layer 903are transparent or translucent but the secret security code pattern 905is not. If the secret security code pattern 905 is made of metal and notof printing ink, it is no problem to place it against the inner layersince materials like metal are much more resistent to the erosion ofmolten polymer resin than printing inks.

If the invention is applied only to produce secret security codes, it isnot necessary to use transparent layers at all. In the simplest of suchembodiments the injection moulded product is made as has been describedabove in association with FIGS. 5 and 6, with the exception that allused polymer resins are opaque to visible light.

FIG. 10 illustrates schematically the production of an injection mouldedproduct for which there is provided a single foil 1001, which comprisespatterns 1002 on at least one surface thereof. The foil is preformed andplaced into a mould, where a layer of (preferably) at least partlytransparent or translucent material is injection moulded on top of thepatterned foil 1001 to constitute an outer surface 1003 of the injectionmoulded product. FIG. 11 illustrates schematically a similar processwhere the difference to FIG. 10 lies in the fact that the patterns 1102are placed on the inside of the foil 1101 instead of that side thatcomes against the injection moulded top layer 1103. The advantage of theprocess of FIG. 11 is the better resistance of the patterns 1102 againstthe conditions occurring during the injection moulding step.

A method for manufacturing the injection moulded structures of FIGS. 10and 11 is easily produced by slightly modifying the method of FIG. 6.The modification includes leaving out steps 607, 608 and 609 andarranging the resin injecting step 612 so that resin is injected on topof the foil instead of below it as was previously explained.

The exemplary embodiments of the invention presented in this patentapplication are not to be interpreted to pose limitations to theapplicability of the appended claims. The verb “to comprise” is used inthis patent application as an open limitation that does not exclude theexistence of also unrecited features. The features recited in dependingclaims are mutually freely combinable unless otherwise explictly stated.

1. An injection moulded product, comprising: a first injection mouldedlayer having an external surface and an internal surface, of which theexternal surface is directed towards a front face of the injectionmoulded product; a foil attached to the first injection moulded layer,the foil having a first side and a second side; and at least one patternon the foil, wherein the foil is attached to the internal surface of thefirst injection moulded layer.
 2. An injection moulded product accordingto claim 1, wherein the first side of the foil is next to the internalsurface of the first injection moulded layer, the pattern is on thefirst side of the foil, and the first injection moulded layer istransparent or translucent to visible light at a location that is nextto the pattern.
 3. An injection moulded product according to claim 2,wherein the whole first injection moulded layer is transparent ortranslucent to visible light.
 4. An injection moulded product accordingto claim 3, wherein the first injection moulded layer comprises visualeffect particles embedded in the injection moulded substance.
 5. Aninjection moulded product according to claim 3, wherein the firstinjection moulded layer comprises a colouring agent mixed into theinjection moulded substance.
 6. An injection moulded product accordingto claim 1, wherein the first side of the foil is next to the internalsurface of the first injection moulded layer, the pattern is on thesecond side of the foil, and the first injection moulded layer and thefoil are transparent or translucent to visible light at a location thatis next to the pattern.
 7. An injection moulded product according toclaim 1, wherein the foil consists of a single base foil, on the surfaceof which the pattern is located.
 8. An injection moulded productaccording to claim 1, wherein the foil consists of a base foil having anunpatterned side, which is next to said first injection moulded layer,and a number of other foils.
 9. An injection moulded product accordingto claim 1, wherein: the injection moulded product comprises a secondinjection moulded layer; and the first injection moulded layer, the foiland said second injection moulded layer constitute, in this order, anintegral layered structure where the first side of the foil is next tothe internal surface of the first injection moulded layer and saidsecond injection moulded layer is next to the second side of the foil.10. An injection moulded product according to claim 9, wherein the wholesecond injection moulded layer is transparent or translucent to visiblelight.
 11. An injection moulded product according to claim 9, whereinthe foil consists of a base foil having an unpatterned side, which insaid integrated layered structure is next to said second injectionmoulded layer, and a number of other foils.
 12. An injection mouldedproduct according to claim 9, wherein the foil consists of a base foilhaving an unpatterned side, which in said integrated layered structureis next to said second injection moulded layer, a number of other foilslaminated with said base foil into a laminated foil structure, andpatterning on at least some surfaces of said other foils.
 13. Aninjection moulded product according to claim 9, comprising another foiland another injection moulded layer, which are together in this ordernext to said second injection moulded layer.
 14. An injection mouldedproduct according to claim 1, wherein: it comprises a secret securitycode which is a pattern on the foil; said secret security code is withinsaid integrated layered structure surrounded by layers that are opaqueto visible light but translucent to certain other electromagneticradiation; and said secret security code is essentially less translucentto said other electromagnetic radiation than the layers surrounding it.15. An injection moulded product according to claim 1, characterised inthat it is a cover for a mobile telecommunications device. 16.-19.(canceled)